Convective structure of two Atlantic 2010 rapidly intensifying tropical cyclones

Tropical cyclone rapid intensification remains poorly anticipated by operational models and observational platforms potentially as a result of interactions occurring on the convective and microscales within the tropical cyclone core. Numerous structural features have been linked by prior studies to rapid intensification such as: convective axisymmetry and asymmetry, vortical hot towers, convective bursts, and mesovorticies.

We evaluate these paradigms in the context of 1-km Weather Research and Forecast model simulations of the rapid intensification of Hurricane Earl and “rapid genesis” of Tropical Storm Karl, observed during NASA's Genesis and Rapid Intensification Project (GRIP) during 2010. Distributions of convective towers and condensational heating are evaluated over time, height, radii, and azimuth to isolate signals associated with rapid intensification. The model output is compared qualitatively to structural characteristics of these systems collected aboard the NASA DC-8 aircraft during the Genesis and Rapid Intensification Processes field campaign by the Advance Precipitation Radar Second Generation (APR-2). The long duration of each flight will allow simulated storms' structural characteristics to be evaluated for long time periods at a higher resolution than of the model. Structural evolution prior to and during each cyclone's rapid intensification periods are intercompared among models and radar observations to examine the organization of convection and the mechanisms by which the convection causes the storms to intensify.